Method of and means for joining tubes to walls



March 23 1926.

L. M. ELLIS ET AL rmuon OF AND MEANS FOR JOINING TUBES TO WALLS Filed Dec. 13. 1920 4 Sheets-Sheet 1 fimemioms Law/1,5 77L. Ellis. Tree,

H. m h/W,

March 23,1926. 1,578,019

L. M. ELLIS ET AL METHQD OF AND MEANS FOR JOINING TUBES T0 WALLS Filed Dec. 13, 1920 4 Sheets-Sheet 2 March 23' 1926. 1,578,019

L. M. ELLIS ET AL METHOD OF AND MEANS FOR JOINING TUBES T0 WALLS Filed Dec. 15, 1920 4 Sheets-Sheet 3 March 23 1926. 1,578,019

L. M. ELLlS ET AL METHOD OF AND MEANS FOR JOINING TUBES TO WALLS Filed Dec. 13, 1920 4 Sheets-Sheet 4 WWW/76 Wvww 5" 1 1 m... 5T-

v 25 l c I) x I \Vi :1 =1 x ping 1 Q- 4 i mmmm WY/7% I clnumrj LQZUJLSJ 771.1111; Yreelm H.L$1i ByMm-dzMz/ (Hiamays Patented Mar. 23,1926 I UNITED. STATES P TENT 1,578,019 OFFICE.

LEWIS I. ELLIS AND FBEELAND II. LESLIE, CHICAGO, ILLINOIS; SAID ELLIS .LS-

BIGNOB OF HIS ENTIRE RIGHT TO WINSLOW SAFETY HIGH PRESSURE BOILER COMPANY, OF CHIGAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

I mansion or AND nuns non omnvo Tunas '10 warms.

Application filed December 18, 1920. Serial No. 430,578.

, To all whom it may concern:

Be it known that we, Lnwrs M. ELLis and FREELAND H. LESLIE, both citizens of the United States, residing at Chicago, in the i county of Cook and State of Illinois, have invented a certain new and useful Improvement in Methods of and Means for Joining Tubes to Walls, of which the following is a full, clear, concise, and exact description,

reference being had to the accompanying drawings, forming a part of this specification.

Our invention relates to the method of and means for joining tubes to walls such for instance as the heads of boilers or joining a tube to another tube for the purpose of making a tight joint between them.

In the construction of boilers it is desirable to connect the tubes to the heads in the 24) case of a fiue boiler or to connect the tubes to aheader in the case of a water tube boiler by a joint which will stand a relatively high degree of heat. such for instance, as would be caused by heating of the boiler above the i water level.

The invention is not to be limited to pressure containing vessels such as boilers, but may be employed wherever a tube is to be joined to a wall whether the wall be a fiat ac sheet or a curved sheet and whether the joint is to be fluid tight or not.

We shall describe our invention in connection with the production of a joint betweenparts of a boiler, but this is merely 535 for purpose of illustration and not -for limiting the invention thereto.

The invention is particularly adapted for rapid and uniform work since it is primarily secured through electric heating which pertlt mits of rapid and accurate heating particularly where the heating is required to be limited to aparticular locality.

We provide means for and a method of forming first of all a closed mechanical jointwhich shall have great mechanical strength forthepurpose of withstanding stresses such as would be encountered in a high pres sure boiler and we provide further means formaking the joint tight first by mechani- IO cal contact and second by a molecular union. Under this latter form, we provide a joint which is sealed by a brazed or similar joint where the joining metal is of a melting point I joined or by a weld of the tube to the wall either directly or through the medium of an interposed member which localizes the seal.

In order to apprise those skilled in the art how to practice our invention, we shall now describe in connection with the accompany ing drawings an embodiment of our invention and the preferred manner of practicing the same. In the drawings:

Figure 1 is a diagrammatic showing of the manner of joining one tube to another tube according to our invention;

Figure 2 shows a joint made between a tube and a flat wall;

Figure 3 is an elevational view partly in section showing the manner of making up the joint between a tube and a header;

Figure 4 is an elevational view of a pair of clamping jaws or dies such as may be employed in making the joint of Figure 2;

Figure 5 is a similar view of a pair of clamping jaws or dies such as may be employed in connection with the joint shown in Figure 3; and

Figure 6 is a sectional view similar to Figure 2 showing a joint employing a gasket;

Figure 7 is a similar sectional view show ing the use of a brazing or welding com pound in the joint;

Figure 8 is a View similar to Figure 1 showing a modified form of die adapted to make the joint in two stages such as is advisable in case of a weld;

Figure 9 is a fragmentary view partly in section of a modified form of die;

Figure 10 is a view similar to Figure 1 showing the manner of forming-a localized weld by means of a special gasket or wire ring; and

Figure 11 is a similar view of a two part expandin die for welding similar to those shown in igures 8 and 9.

According to our invention, we first cut a hole through the wall, into which the tube is to be fastened,vthen we heat the end of the tube locally while it is inserted in the aperture in the wall, then upset the end of the tube to form a flange on the free end and a head on the opposite side of the wall so that the wall is compressed between the bead and the flange, and expand the interior of the. tube, into the aperture so that the Wallis mm lower than that Of the tubes and walls to be gripped on the, Surface defining thg apgrture and upon the two opposite sides of the wall. 4

This is the fundamental action involved, butthe process may be carried further. Plain mechanical contact ma be relied upon to seal the joint with or without an interposed gasket. If a molecular union is desired the heating of the wall independently is preferable. This may be done either simultaneously with the heating of the tube or it may occur partly after the heating of the tube. When aweld is to be made the metal parts to be joined must be heated to a welding heatand then firmly pressed together.

As shown in Figure 3, the tube 1 is projected through an aperture in the header 2 so that sufliclent stock lies on the inner sideof the wall 3 to form a flange when the joint is made. The tube 1 isnshown as closely fitting within the aperture in the wall 3, but

a this is not essential'as will be apparent from f the fact that theend of the tube is expanded into the aperture when the joint is made.

' The clamping jaws 4, 5 shown in Figure 1 are fastened upon the tube 1 adjacent the wall 3 and the electrode or die member 6 is inserted in the open end of the tube. The die or electrode 6 rests upon a suitable electrode stem 7 which is preferably water cooled as indicated by the pipes 8, 9. The stem 7 is gripped between suitable jaws 10, 11 which are connected b a suitable conductor 12 to a source of we ding current, the

other terminal of which is connected to theclamping members 4,- 5 by means of the conductor 13. These conductors are shown-diagrammatically,-it. being understood that the clam s 4, 5 and 10, 11are placed in electrical and mechanical contact with suitable gripping means which maintain these parts ma heating or welding circuit. The clamps at 16 in Fi w ich occur substantially 4, 5 grip the tube 1 circumferentially and the stem 7 pushes the die member 6 axially into the open end of the tube. The die member 6 and the clamps 4, 5 are moved toward each other as soon as the flow of current has heated theend of the tube locally. The end ofthe tube becomes plastic by the heating of the electric current and the pressure axially u on the tube produces three effects, all of simultaneously, namely, first the formation of a head or ring upon the outside of the wall 3 adjacent the edges of the aperture; at the same time,- the pressure of the die member 6 against the open end flanges the end of-the tube as shown re '1. At the same time, the forward en of the die member 6 which has a. somewhat wedge-shaped end forming a v plug or stud portion 17, is forced into the openend of the tube, expanding the metal of the tube outwardly into contact with the walls defining the aperture as thewalls of the tube are thickened. Thus, the end of the tube grips the wall 3 on three sides,

namely, on the interior peripheral surface of the aperture, upon the outer surfaceof the cally because of the flanges formed on each side of the wall to which the tube is joined. The joint is also made tight because of the expandin of the tube into the aperture and because t e shrinking of the metal of the end of the tube, u on cooling, tends to make the joint firm an ti ht.

When the jaws such as shown in Figure 4 are used, the head will be unsymmetrical with regard to the true line of intersection. Thus, for instance, in Figure 5, the bead may be formed mostly or wholly along the sides. By proper control of the form, position and movement of the dies, the extent and location of the beads and flanges may be I ure 3, a form of gripping jaws 18, 19 such as shown in Figure 5 may be employed for forming the bead evenly around the line of intersection of the two tubes. Thus, there is a tendency for the head 15 to be formed as shown. at 20 in Figure 3 following more closely the line of the intersection and thus maintaining the joint more nearly uniform and consequently more likely to be permanent.

In Figure 2 we have shown a tube 21 joined to a flat plate 22 by our improved process and joint. The tube 21 has the head 23 nipon the outside, the flange 24 upon the insi e and the walls 25 expanded into the opening in the plate 22, all in the same manner as indicated in Figures 1 and 3 in connection with the other.

For making the joint shown in Figure 2 the flat electrodes or gripping jaws 26 and 27 are preferable. At the same time the flangin and expanding die corresponding to the ie as shown at 6 in Figure 1 is employed,'such die having a suitable flat flanging surface for turning out the flange 24.

As shown in Figures land 3, where it is desired to join tubes such as shown at 1 to a header such as shown at 2, it is necessary to secure suitable pressure for collapsing or up-setting the end of the tube and to this end, we may cut an opening such as shown at 28 back of the joint so that the stem 7 may be inserted for making the joint. The die or electrode memberv 6 may be inserted joiningof one tube to an- Ill from the end of the header and placed over the end of the stem 7 for making the joint.

In Figures 6 and 7, we have indicated modifications, wherein we depend upon additional, means for securing a fluid tight In producing the joint shownin Figure 6, we first slip a gasket suchas is indicated at over the end of the tube 31 u on the inner side oi the wall 32. Therea ter the clam s, such as shown in either Figure 4 or Figure 5, as the case may be, are attached to the tube and the die such as shown at 6 in Figure 1. is then inserted in the open end of the tube, and the joint is made in the same manner as previously described, the gasket 30 being, compressed between the flan e 33 and the wa1l-32. The gasket is pref erably placed upon the side of reatest fluid pressure andcould be located the bead 34 and the wall 32. I

In Figure 7, we have indicated a joint in which we have interposed soldering, brazetween ing or welding material, as shown at 35.

This material forms a molecular union between the tube and the wall. In making the joint, the material preferably is placed upon the tube in the form of a ring or washer. This rin or washer is compressed as the joint is ma e and at the same time, it is heated to the r uired temperature for forming the molecu ar union. We prefer to form a brazed joint in which we use s elter. However, we do not wish to limit t e invention to this particular method.

When a weld is desired, it is necessary to bring the surfaces to be joined to the roper temperature and to force the same firm y into contact. In Fi ure 8, we have shown a two part die upon t e end of the tube. This die as a base portion 46 supportedupon a hollow water cooled stem 48 and a plug or stud portion 47 fitting into the base portion 46 and resting upon the central water cooled stem'49.

In operation, the tube is gripped in the usual way with the electrode clamps 4445 and the compound die 46-47 is pressed into the open end of the tube 41. The cur-' rent is turned on and the parts brought to a red heat. Then the dies are forced toward each other to form the bead 50 and the flange 51. When these parts are brought into contact with the wall surrounding opening in which the tube is placed, current passes through the bead, the wall 52 and to the die 46 heating the wall 52 to a welding heat then the stems 48 and 49 are pressed further, first to bring the bead 50 and flange 51into engagement with the wall 52 and then to force the 'stud'47into the open end of the tube to expand the same into the The same action may be secured by making a part or all of the die of the expanding type. Thus, forlinstance, as shown in the entire die may be made integral and may be expansible by means of slots such as shown at 54. Figure 11 shows an im provement upon the means shown in Figures 8, and 9 in that the base member 55 is directly water cooled by the pipes 5657 which communicate with a duct or cooling passageway 58 in the base die member 55. This base member is supported upon a stem 59 in the case consisting of a co per tube or sleeve which is connected by the clamps 60 to one terminal of the source of heating current. The base 55 has a stud 61 adapted to enter the end of the tube for expanding the tube when the joint is made. This stud is insulated from the base member as indicated at 62, as. it is not intended that the stud carry any current. The stud is water cooled, as is apparent from the tube 63 and pocket 64.

It has been found that if the stud is electrically joined to the electrode owing to the proximity of the end of the stud to the end of the clamps upon the tube, there is a tendency to overheat the tube between those points. By. the present construction the stud 61 may be brought further into the tube as is necessary for expanding the tube against the adjacent surface of the aperture. The stud 61 is tapered on a relatively long taper so that very considerable pressure can be brought upon the interior surfaces of the tube. a shoulder which overhangs the joint between the stud and the base so that there is no tendency for the metal to catch upon the edges of the joint. I

In the present construction the stud does not, conduct current and hence the tendency is to get a more even heating of the edges of the wall about the edges of the aperture between the bead and flange.

In all the forms of apparatus previously It will be noted that the stud has described the wall to which the tube is to be joined may be heated prior to the formation of the joint. This is particularly desirable when it is desired to make a weld. As shown in Figure 10, two sets of clamps such as shown at 70 and 71 may be mounted upon the wall or header 72 and the entire mass of metal between these clamps is heated while the end of the tube 1 is being heated.

In the present case, we form a seal between the flange 16 and the wall 73 by means of a wire ring 74 which is placed over the end of the tube 1 before the tube is heated. We provide a switch 75 which is designed to chan e the flow of. current of the two sources 6 and 77, in such a. manner as to heat these surfaces which are to be joined. In the full line position of the switch 7 5, the current from the source 7 7 flows through the header 72 between the clamps 7 -7 1, and

the current from the source 7 (iflows through the end of the tube 1 between the clam s l5 and the die'6. As soon as the end of e' tube is softened, the dies 6 and clamps 45 are forced together and the bead and flange 16 are formed. At this time, the wire ring 74 is clamped between theflange 16 and the wall 73. The header walls bein also under heat the parts are substantia ly at welding temperature.

The switch 7 5 is thrown while the end oi the tube is still being collapsed. The result is that the adjacent surfaces are joined together.

If desired, the wire ring 74 may be employed to insure the formation of a limited line of weld. At the time the switch is thrown, the flow of current from the wall 73 through the wire 7 4, flange 16 and electrode 6 and heats the wire 7 4 to welding heat, I

the effect being a localization of the heating and an intense heating of the wire and the adjacent surfaces somewhat as in the case of a spot weld. When the wire ring 74 is employed, the preliminary heating of the wall 73 may be dispensed with.

We do not intend to be limited to the preexact procedure that we have above outlined as our invention is defined in the appended claims.

We claim: p 1. The method of securing a tube. into "an aperture in awall which comprises heating the end of the tube locally in front of and back of the wall. then swagingthe tube by pressure applied axially to compress the walls of the tube into a bead or flange .at one side of the wall.

2. The method of securing a tube into an aperture in a wall which comprises heating the end of the tube locally while in placev in the aperture, then compressing the tube axially to raise a bead upon each side of the wall about the aperture, and in contact therewith. and expanding the end of the tube within the aperture'to fill the aperture.

4. The method of securing a tube into an aperture in awall which comprises heating the end of the tube while in place in the ap-' erture to soften the metal on each side of the raise a bea in contact with the wall c'ompressm e end of the tube axially to about the aperture, expanding theend of the tube into a flange fitting against the inner surface of the wall and expanding the tube wall, grippingfhe tube on tlie outside and.

on the outer surface of the tube within the aperture to cause the tubeto fill the same.

.5. The method of oining a tube to a wall which comprises pro ecting the tube throu h an aperture, gripping the tube mechanica Iy outside the wa thrusting a cooperating die and electrode into the end of the tube on 3 the other side of the wall and simultaneously heating and compressing the end of the tube, then forming a bead upon the tube in front of the wall, flaring out the end of the tube against the'inner surfaceof the wall and expanding the tube into the aperture.

6. The methodof joining a tube into an aperture in a wall which com rises projecting the tube through the wal with its free end adjacent one side of-the wall, heating the tube locally from its end to a' pointbeyond the opposite side of the wall, compressing the heated end axially to form the wall of the tube immediately outside the edge of the aperture into a bead lying against the edge of the aperture, flaring out the free end of the tube against the adjacent surface ofthe wall about the aperture and expanding the tube radially to fill the up -erture.- cise details of construction, nor tothe pre-v cise forms or proportions, nor indeed to the 7. In means for joining a tube to a wall, a' gripping die and electrode for gripping a tube, the end of said die conforming-to. the line of intersection of a tube and the wall to which it is joined, and a cooperatingdie having an expanding core and aspreading flange, said spreading flange conforming to the flange formed about the end of a tube joined.

8. In combination, a gripping die: 'for gripping atube to be joined to a wall; and

an expanding. and flanging die for expanding the end of the'tube and'flanging out the q end into contact with the wall.

to which j it is J,

59."In-; combination, a gripping a. .for-

grippjin ga tube to be joined to a: wall, and an expandmg and flanging'die for expanding the end of the tube and flanging out the end into contact with the wall, and electrical connections for each of said dies whereby ghe'tube may be heated in contact with said tween the clamp and the die, said die com- 10. In combination, a cl'amp for'a tube,- a forming die for the end of the tube, and means for causing arelative movement benI-i 1 prising a base member and a stud member and means for causing the stud to expand i the end of the tube and the base member to flange out-the end of the tube.

In a die 1 for treating the end of a tube, a flange forming base member and a stud member movable separately for expanding the end of the tube adjacent the flanges.

12. The method of securing a tube in. an aperture in a wall which consists in placing an end of the tube in the aperture and compressing the tube to form a bead therein on one side of the wall. I

13. The method of securing a tube in an aperture in a wall which consists in inserting an end of the tube in the said aperture,

compressing the tube to form a bead therein on one side of the said wall and expanding the said end of the tube in the aperture.

14. The method of securing a tube in an aperture in a wall which consists in inserting an end of the tube in the said aperture and compressing the tube to form a ridge therein on one side of the said Wall and to flare the said end of the tube outwardly on the other side of the wall.

15. The method of securing a tube in an aperture in a Wall which consists in insertingan end of the tube in the aperture, heating the tube while in place in the aperture, compressing the tube to form a ridge there' on one side of the said wall, and expanding'the end of the tube in the said aperture. I

16. The method of securing a tube in a wall which consists in inserting an end of the tube in an aperture in the said wall, heating the tube while in place in the aperture, and then compressing the tube axially to form a ridge therein, on one side of the wall and to cause the end of the tube to be flared outwardly on the other side of the wall.

17. The method of securing a tube in another side of the wall and expandingthe end of the tube in the said aperture.

18. The method of securing a tube in an aperture in a wall which consists in inserting the tube in the aperture, heating the tube and then compressing the tube axially to raise a ridge therein upon each side of the wall about the aperture in contact therewith.

19. In combination, means for gripping a tube to be secured in an aperture in a wall, means for compressing the tube axially to form a. ridge therein on one side of the wall, and a flanging member for causing the end of the tube to be flared outwardly on the other side of the wall.

20. In combination, means for gripping a tube to be secured in an aperture in a w. ll, means for heating the tube, a member for compressing the tube axially to form a ridge therein on one side of the wall and a flanging and expanding member for causing the end ofthe tube to be flared outwardly on the other side of the wall and for expanding the end of the tube in the said aperture.

21. In combination, die means for gripping a tube to be joined to a wall, and plunger means for expanding the end of the tube and for flangingit out into contact with one side of the wall, said plunger means be ing adapted to have longitudinal pressure transmitted therethrough to the end of the said tube, said die means having longitudinal pressure imparted thereto in an opposite direction to that imparted to said plunger means and being adapted for gripping the said tube in proximity to the said wall for forming a bead in the tube in contact with 

